Starting means for gas or vapor electric apparatus.



. PATBNTED PEB. 28, 1905. P. H. THOMAS.

STARTING MEANS FOR GAS 0R VAPOR ELECTRIC APPARATUS.

2 SHEETS-45mm: 1.

APPLIUATION FILED HAY 6. 190s.

inve/dor .......sss/ A .....1 m

PATENTED FEB. 28, 1905.

No. 783,480. A

E. E. THOMAS. STARTING MEANS EOE GAS 0E VAEoE ELEGTETG APPARATUS.

APPLIOATION FILED MAY 6. 1903.

2 SHEETS-SHEET 2.

Ely-5 y .LA-1M A TrmhAffy Winesses Amm i no. 783,480.

` STATES Patentec'i February 28, 1905.

PATENT OFFICEO PERCY H. THOMAS, OF PlT'lSBURG, PENNSYLVAIA, ASSIGNOR TO COOPER HEVITT ELECTRIC COMPANY, A CORPORATTON OE NEW YORK.

STARTING IVIEANS FOR GAS OR VAPOR ELECTRIC APPARATUS.

SPECIFICATION forming part of Letters Patent No. 783,480, dated February 22B, 1905.

Original application tiled February 3, 1903, Serial No. 141,697. Divided and this application led May G, 1903. Serial No. 155,924.

To {1J/Z 'l1/"71,0111, 'lit may cm1/carat:

Be it known that I, PERcY H. THOMAS, a citizen ofthe United States,and a resident of Pittsburg, county of Allegheny, State of Pennsyl- 5 Vania, have invented certain new and useful Improvements in Startingl Means for Gas or Vapor Electric Apparatus, of which the following is a spceiiication.

It has been proposed, in connection with the ro gas or vapor electric apparatus invented by Peter Cooper Hewitt and described in one or more of its forms in certain Letters Patent of the United States issued to him on the 17th day of September, 1901, to utilize as a means i 5 for assisting in the starting of such apparatus what is called a starting-band]7 located on the outside of the containing' -tube in the neighborhood of one of the electrodes and connected by a wire with the side of the cirzo cuit connected to the `other electrode. ln the operation of apparatus of this character it is found that there exists a reluctance to starting, this reluctance appearing' particularly at the electrode which is for the time being' the negative electrode. When, therefore, current is applied to the terminals of the apparatus, there is created at or near such elec,

trode a strain which is usually not overcome by the voltage which is afterward applied to 3o the operation of the apparatus. It appears, nevertheless, to be true that this strain tends toward a breakingr down of the reluctance and that when a higher potential is applied in such a direction as to assist the strain this reluc- 3 5 tance may be broken down, and the apparatus will then operate until a cessation of the current supervenes or a reversal of its direction. Means have already been devised for breakingI down the reluctance and are now known 4o in the art. lV henmeans are provided for breaking down the electrode reluctance and for maintaining,r it in that condition, the apparatus will operate upon direct current during' the continuance of such current, or in case an 4 5 alternating current is applied to the terminals of the apparatus like phases will traverse the apparatus, while opposite phases will be suppressed, owingI to the fact that the tendency of such phases to pass through the apparatus i is resisted by a reluctanccat the opposite electrede, which then becomes thc negative electrode with respect to the direction of the current.

The present invention aims to provide a simple starting' means for apparatus of this 55 class in which no extraordinary pressure is applied to the terminals of the apparatus, but in which an additional electr-emotive force is introduced through the walls of the apparatus by means of the starting-band or other suitable devices, whereby the strain at or near the electrode is increased to the breakingpoint and current is made to pass through the apparatus. This can be accomplished with very little expenditure of energy, Moreover, the time when the strain approximates the breaking-point-that is to say, the point where it isiadapted to break down the reluctance at the electrode-can be predetermined by means of my invention in such a manner that when the accumulated strainis reinforced by an impulse from the mains without any increase of electromotive force in the said mains the reluctance will be broken down andthe apparatus started. 7 5

In carryingI out the invention l may make use of a transformer the primary of which is connected between the mains of an alternating-current circuit leading to the terminals of the apparatus and the secondary of 8O which is connected between either of said mains and the starting-band. ln circuit with the primary l may place a resistance and an ind uctance, by means of which the effects upon the secondary of the transformer are properly L timed with relat-ion to the electromotivc force of the mains. [t will be understood that other or different means may be used for securing the application of the critical strain from the secondary circuit at the proper moment of time with relation to the electromotive force in the main circuit. Any means for securing the desired relation between the time of the application of the critical strain and the phase of the electromotive force of the supply-circuit, may be used withoutdeparting` from the principle of the present invention.

The accompanyingI illustrations show means suited for the process described, although it may be applied at the starting-band, and the will be understood that wide variations from g the particular devices shown may be made.

Figure 1 of thc drawings is a diagram illustratingone possible embodiment of my invention. Fig. 2 is a diagram illustrating the employment of the invention in connection .j

the phase of the main source of supply which with a three-phase source. Fig 3 is a diagram of the electromotive forces of the threephase supply-circuit, and Figs. 4 and 5 illustrate modifications.

Referring to the drawings, l is a suitable container inclosing a conducting gas or vapor, which may Vbe mercury-vapor. The electrodes appear at 2 and 3 and the starting-band at 4. The starting-band might be applied outside of the electrode 3 instead of where it is shown in the drawings, near the electrode 2. At 5 and 6 arc shown the lead-wires running through the walls of the container to the electrodes 2 and 3, respectively. To these electrodes are connected the mains 7 and 8, leading' from an alternating-current source. I connect in the circuit between the mains 7 and 8 the primary 9 of a transformer, and I may also connect in series with the said primary a resistance 10 and an inductance 11. The secondary of the transformer is indicated at 12, and its terminals are connected through an adjustable switch 13 with starting-band 4 and the main 8. The wire connecting with the main 8 might be joined to the main 7 instead of 8 if for any reason it should be found desirable. By the proper adjustment ofthe devices in the cross-circuit which includes the primary 9 it is possible to accelerate in time the production in the circuit of the secondary 12 of an electromotive force approximating the breaking-point, and if this electromotive force be then reinforced byv an impulse of proper direction from the mains and if this is caused tooccur at `the phase of the supply electromotive force at which it is desired to start the apparatus the operation will begin and continue until the direction of the current changes, and the operation will be repeated with each successive phase of the proper direction.

In Fig. 2, 13 represents a source of threephase alternatingl currents having a primary 9, connected between the coils 14 and 15, and the secondary 12, connected between the coils 16 and the starting-band 4. In the circuit of the secondary I here introduce a spark-gap, (represented at 17,) the usual means of adjustment being supplied. The main variation illustrated in this figure as compared with that shown in Fig. 1 is that by reason of the presence of the spark-gap no electromotive force is applied at the starting-band until suflicient has accumulated to bridge the gap and apply to the starting-band a strain approximating the maximum strain required for breaking' down the reluctance at the electrode. By this means a sudden rush of current of increased density time at which such application is made may be regulated by the adjustment of the. sparkgap apparatus.

Fig. 3 illustrates the phase relation of the electromotive forces just described in connection with Fig. 2, in which case 2O represents is used for the device 1, and 21 represents the phase from which the primary 9 o f't-he eXciting-transformerA is supplied, and 22 represents the third phase of the three-phase supply-circuit, which in Fig. 2 has not been used.

The electromotive forces which are applied to the starting-band or'otlier part of the apparatus as herein described are not'necessarily derived from the source of alternating currents through the action of a transformer; but such electromotive forces may be supplied from independent sources or from the source leading to the terminals of the apparatus through other devices than ordinary transformers.

Moreover, assuming the proper time relations between the electromotive forces of the supply-circuit and those applied to the appatus through the transformer or through such other sources of electromotive force as are indicated in the preceding paragrajih, the application of the elcctromotive forces adapted to produce a critical strain may be made, say, to a third or supplemental electrode instead of to the starting-band. This arrangement is illustrated in Fig. 4, where a supplemental electrode is shown at 23 as being connected to one terminal of an autotransformer 24, the other terminal of which is joined to the main 8.

Fig. 5 illustrates still other means for producing a critical strain within the apparatus, such means consisting of a plate 30 outside the Wall of the container and a plate 31 on the inside thereof, the two plates, with the intervening wall, which must be of insulating material, constituting a condenser. I may form on the inner plate 31 a projecting lug 32, provided with a point, as shown, to facilitate the discharge.

The supplemental electrode 23 shown in Fig. 4 and the condenser constituted by the plates 30 and 31 on the opposite sides of the container-wall and the point 32, projecting inward from the plate 31, as shown in Fig. 5, constitute substitutes for or supplements to the starting-bands illustrated in Figs. 1 and 2. It is found that such supplemental devices serve, in connection with the apparatus described herein, to form a point at which a critical strain may be applied to the apparatus tending to break down the negative-electrode resistance.

This application is a division of my application h'led February 3, 1903, Serial No. 141,697.

I claim as my invention- 1. The combination with a source of electric currents, of a gas or vapor electric apparatus IOO having electrodes, a starting-band near one of the electrodes, conductors leading to the said electrodes, and a transformer deriving current from the said source, the secondary of the transformer being connected to the starting-band and to one of the mains, and devices interposed in .the transformer-circuit for accelerating the electr-emotive force delivered by the secondary thereof with relation to the electromotive force of the source.

2. The combination with a source of electric currents, of a gas or vapor electric apparatus having electrodes, a starting-band near one'of the electrodes, conductors leading to the said electrodes, and a transformer deriving current from the said source, the secondary of the transformer being connected to the starting-band and to one of the mains, and a resistance and an inductance in the primary circuit of the transformer serving to accelerate the electromotive force delivered by the secondary.

3. The combination with a source of polyphase electric currents, of a gas or vapor electric apparatus, electrodes therefor, conductors leading' from terminals of the source to the gas or vapor apparatus, a transformer deriving' current from the source, the secondary of the said transformer being connected to one of the leads from the source and also to the starting-band, and a spark-cap interposed in the secondary circuit.

4f. The combination with a source of polyphase electric currents, of a gas or vapor electric apparatus, electrodes therefor, conductors leading from terminals of the source to the gas or vapor apparatus, and a transformer deriving current from the said source, the secondary of the transformer being connected to the starting-band and one of the mains.

5. The combination with a source of polyphase electric currents, of a gas or vapor electric apparatus having electrodes and characterized by a reluctance to starting appearing' at one of the electrodes, whereby an electric strain is produced at the'said electrode, conductors leading to the electrodes and means for suddenly delivering to the apparatus accelerated electromotive force, adapted to increase the strain at the said electrode, and means for increasing the strain to the critical point through the medium of the additional electromotive force.

6. The combination with a source of polyphase electric currents, of a gas or vapor electric apparatus having electrodes and characterized by a reluctance to starting appearing at one of the electrodes whereby an electric strain is produced at the said electrode, and a transformer deriving current from the source, the secondary of the said transformer being connected to one of the leads from the source, and also to the gas or vapor apparatus to such a point as to increase the strain, the conditions being such that the electromotive force from the secondary shall have a predetermined phase relation to the electromotive force of the source.

7. rlhe combination with a source of electric currents, of a gas or vapor electric apparatus having electrodes, a starting-band near one of the electrodes, conductors leading to the said electrodes, and means for suddenly delivering to the starting-band energy accumulated by a dielectric.

Signed at New York, in the county of New York and State of New York, this 28th day of April, A. D. 1903.

PERCY H. THOMAS. Witnesses:

WM. H. CAPEL, GEORGE H. STooKBRIDGE. 

